Conductance, Resistance and Current.

Question 1

Give the definition of an electric current. Then give the units.

Answer 1

Amount of charge per unit time. The units is ampere (C/s).

Question 2

What direction does the electron flow go in?

Answer 2

From the negative to the positive terminal.

Question 3

What happens to the (conduction) electrons, when no current is passing through.

Answer 3

The electrons move randomly, with no net motion in any direction.

Question 4

Explain the term drift speed.

Answer 4

When a current is passed through a circuit, the conduction electrons still move randomly. However, they now sort of drift with a drift speed in the direction opposite that of the applied electric field that causes that current.

Question 5

Define the difference between resistance and resistivity.

Answer 5

The ratio of the voltage V applied across the material to the current I to the material.

Resistivity is a material property.